Yamagata Castle is mostly ruins now, but its moats, gates, and stonework still give the city a centre. The grounds are laid out as Kajo Park, a pleasant place for a first walk after arriving by train.
The castle was expanded under Mogami Yoshiaki, who turned Yamagata into a serious castle town. Come in cherry blossom season if you can, but even outside spring the open moats and rebuilt gates help explain the city's shape.